package com.li.common;

import java.io.UnsupportedEncodingException;

/**
 * 取得给定汉字串的首字母串,即声母串
 * Title: ChineseCharToEn
 * @date 2004-02-19 注：只支持GB2312字符集中的汉字
 */
public final class ChineseCharToEn {
  private final static int[] li_SecPosValue = { 1601, 1637, 1833, 2078, 2274,
    2302, 2433, 2594, 2787, 3106, 3212, 3472, 3635, 3722, 3730, 3858,
    4027, 4086, 4390, 4558, 4684, 4925, 5249, 5590 };
  private final static String[] lc_FirstLetter = { "a", "b", "c", "d", "e",
    "f", "g", "h", "j", "k", "l", "m", "n", "o", "p", "q", "r", "s",
    "t", "w", "x", "y", "z" };
  
  /**
   * 取得给定汉字串的首字母串,即声母串
   * @param str 给定汉字串
   * @return 声母串
   */
  public String getAllFirstLetter(String str) {
    if (str == null || str.trim().length() == 0) {
      return "";
    }
    
    String _str = "";
    for (int i = 0; i < str.length(); i++) {
      _str = _str + this.getFirstLetter(str.substring(i, i + 1));
    }
    
    return _str;
  }
  
  /**
   * 取得给定汉字的首字母,即声母
   * @param chinese 给定的汉字
   * @return 给定汉字的声母
   */
  public String getFirstLetter(String chinese) {
    if (chinese == null || chinese.trim().length() == 0) {
      return "";
    }
    chinese = this.conversionStr(chinese, "GB2312", "ISO8859-1");
    
    if (chinese.length() > 1) // 判断是不是汉字
    {
      int li_SectorCode = (int) chinese.charAt(0); // 汉字区码
      int li_PositionCode = (int) chinese.charAt(1); // 汉字位码
      li_SectorCode = li_SectorCode - 160;
      li_PositionCode = li_PositionCode - 160;
      int li_SecPosCode = li_SectorCode * 100 + li_PositionCode; // 汉字区位码
      if (li_SecPosCode > 1600 && li_SecPosCode < 5590) {
        for (int i = 0; i < 23; i++) {
          if (li_SecPosCode >= li_SecPosValue[i]
            && li_SecPosCode < li_SecPosValue[i + 1]) {
            chinese = lc_FirstLetter[i];
            break;
          }
        }
      } else // 非汉字字符,如图形符号或ASCII码
      {
        chinese = this.conversionStr(chinese, "ISO8859-1", "GB2312");
        chinese = chinese.substring(0, 1);
      }
    }
    
    return chinese;
  }
  
  /**
   * 字符串编码转换
   * @param str 要转换编码的字符串
   * @param charsetName 原来的编码
   * @param toCharsetName 转换后的编码
   * @return 经过编码转换后的字符串
   */
  private String conversionStr(String str, String charsetName,String toCharsetName) {
    try {
      str = new String(str.getBytes(charsetName), toCharsetName);
    } catch (UnsupportedEncodingException ex) {
      System.out.println("字符串编码转换异常：" + ex.getMessage());
    }
    return str;
  }
  
/*  public static void main(String[] args) {
    ChineseCharToEn cte = new ChineseCharToEn();
    System.out.println("获取拼音首字母："+ cte.getAllFirstLetter("黄镇"));
  }*/
}
